The invention relates to a domestic appliance heating apparatus according to the preamble of claim 1.
A domestic appliance heating apparatus is already known from the prior art, having a first heating connection and a second heating connection, each being able to be connected to a supply connection of a supply network. A first switching element is connected between the first heating connection and a first supply connection. To start a heating operating state and thus to heat the heating element, a conduction path is established between the heating element and the supply connections by means of the first switching element. To interrupt or terminate the heating operating state, the conduction path between the heating element and the supply connections is interrupted by means of the first switching element. The first switching element is actuated for example by means of an operating element. The domestic appliance heating apparatus also has a measuring unit with a measurement input, at which a potential is present in the heating operating state. In order to allow unambiguous measurement by means of the measuring unit, a network form of the supply network, to which the supply connections are connected, must be known. The network form depends on the country, so different domestic appliance heating apparatuses could be used, in particular could be marketed, depending on the respective country. When the network form is known, in some countries, for example Europe or Japan, the precise polarity of the heating connections must also be ascertained, as in these countries a zero conductor is present at one of the supply connections. This can be done on the one hand using a complex apparatus, which requires at least one phase recognition device, a control unit and a corresponding relay circuit. On the other hand a corresponding polarity of the heating connections could be ascertained when an electrician and/or fitter in particular connects the heating connections to the supply connections.